The ageing Klingon Bird-of-Prey commanded by Lursa and B'Etor, which crippled the Enterprise-D over Veridian III in 2371 before being destroyed in Star Trek Generations.
In Star Trek Generations the sisters are working with Tolian Soran, trading their protection for his trilithium weapon. Their ship is an old D12 type, a class retired because of faulty plasma coils.
After capturing Geordi La Forge they return him with a transmitter hidden in his VISOR, letting them see the Enterprise's shield frequency on an engineering display. Their torpedoes pass straight through the shields. Riker, Worf and Data answer by sending a pulse that resets the plasma coil and triggers the Klingon cloak, which drops the Bird-of-Prey's shields for a moment. One torpedo destroys it and kills the sisters, but the damage already done causes the warp core breach that forces the Enterprise to separate and its saucer to crash.